The model includes ‘energy use per person’ as a predictive factor rather than focusing solely on economies or populations.

It forecasts that population and economic growth combined with rising energy use per person could significantly increase global energy demand and CO2 emissions, locking the world into more rapid global warming.

“Our model shows we may have less time left than expected to prevent world temperature from rising above these thresholds.

“World population is forecast to increase to over 9 billion people by 2050, which, together with international ‘pro-growth’ strategies, will lead to continually increasing energy demand.

Professor Hankamer said it was vital to move from CO2-emitting fossil fuels and tap into renewable resources to accommodate these increases while controlling temperature..

“The sun is by far the largest renewable energy source,” he said.

“In just two hours it delivers enough solar energy to the Earth’s surface to power the entire global economy for a year – now is the time to make the switch.

“A cost-neutral strategy that governments should consider to fast track this transition is diverting the $500 billion used to subsidise the fossil fuel industry internationally to assist the global renewable sector.”

Dr Wagner said the model challenged the assumption that increases in energy efficiency and conversion would offset increases in demand.

“We have successfully applied our model to world energy demand from 1950-2010 and demonstrated that increases in energy efficiency alone don’t offset the surge in in energy use per person,” he said.

“Simply put, as we get more efficient at manufacturing, goods get cheaper and we buy more.

Dr Wagner said massive increases in energy consumption would be necessary to alleviate poverty..

“Our choices include: continue down a business-as-usual track with 50 per cent of the population on less than $2.50 per day; increase economic growth powered by fossil fuels and speed towards dangerous climate change; or fast-track a transition towards renewables in an orderly manner.

“As 80 per cent of world energy is used as fuels and only 20 per cent as electricity, renewable fuels in particular will be critical.”

Dr Ian Ross from IMB and Professor John Foster from UQ’s School of Economics were integral in developing the model. The work is published in the journal PLOS ONE .